$NetBSD$

--- third_party/libpng/pnglibconf.h.orig	2020-07-15 18:56:31.000000000 +0000
+++ third_party/libpng/pnglibconf.h
@@ -230,8 +230,10 @@
  * This is necessary to build multiple copies of libpng.  We need this while pdfium builds
  * its own copy of libpng.
  */
+#if 0
 #define PNG_PREFIX
 #include "pngprefix.h"
+#endif
 /* end of chromium prefixing */
 
 #endif /* PNGLCONF_H */
